This invention generally addresses testing and verification in a communication system having separate, but connected, networks that are connected together. More specifically, it addresses the testing of one network's ability to respond to queries received from another network in a telecommunication system.
With the increasing trend towards fully integrated global communication networks, standards and compatibility between linked communication networks is an important concern. The facilities and implementation of features provided by networks often differ. Standard protocols have been established to facilitate the transmission of signaling and data between networks. However, these standards do not insure that facilities in a first communication network will interpret and respond to a query received from a second network in a manner anticipated by the second network.
Each network should be tested and validated in accordance with the standards to be followed by a communication system prior to connection to the other networks in the system. Isolating a problem in a communication system having a plurality of interconnected networks can be a difficult task. In many situations, it is difficult to determine which network is causing the problem. Even if general protocols and formats are followed, problems can arise because various implementations in hardware and software by the networks can result in the same query or message being handled differently by different networks. Dissimilar interpretations of a standard protocol can also result in problems.
To facilitate testing, various types of simulators have been utilized to emulate the actions of other networks. In a communications network, simulators may consist of a computer which has been programmed to emulate actions and responses that an external environment would provide to the network or module under test. Ideally, it would be impossible to distinguish the simulator from the network or module being simulated. However, complexity, and hence cost, of simulators increase geometrically with increasing complexity of the environment being simulated. Thus, simulators that emulate an entire network are very complex, costly, and difficult to develop.
As communication systems become more open and allow networks to access more facilities in other networks, the need for testing and problem identification becomes critical. In order to minimize initial problems and quickly solve problems discovered after connection of a network to the system, it is desirable to isolate the network from the system for testing. It is also desirable to utilize as much of the real hardware and software capability of the network under test as possible so that differences between a testing environment and real network operation of the network are minimized. Thus, a need exists for the capability to test a first network's ability to interact with other networks while utilizing as much of the first network's actual hardware and software as possible and to perform such testing without interaction with the other networks or the need for a separate simulator to emulate the other networks.